The invention relates to the field of lasers and more particularly to the field of plasma excitation-recombination lasers.
Applicants have demonstrated that recombination lasers could be generated in the recombining plasma of a laser-vaporized metal (Cd) by use of the relatively low energy (as low as 0.5 mJ) output of focused lasers. This work was documented in an article entitled, "Recombination Lasers in Nd and CO.sub.2 Laser-Produced Cadmium Plasmas", by W. T. Silfvast, L. H. Szeto and O. R. Wood II, Optics Letters, September, 1979, Vol. 4, No. 9, pp. 271-273. This result was obtained by allowing the laser-produced plasma of the target material to expand into a low pressure background gas which provided control of the plasma expansion and increased the electron cooling rate, thereby increasing the recombination rate. Further work by applicants has indicated that segmentation of the plasma in the focal region where it is produced by cylindrical focusing is significantly more effective in generating a recombination laser in xenon gas than is the generation of the plasma by a continuous line focus. A 24-fold increase in Xe laser output was obtained for the segmented focus plasma as compared to the continuous line focus plasma for the same input energy. This increase was attributed to the larger volume of cool gas surrounding the plasmas which allowed greater plasma expansion and thereby increased the plasma recombination rate. This work was documented in an article entitled, "Ultra-High-Gain Laser-Produced Plasma Laser in Xenon Using Periodic Pumping" by N. T. Silfvast, L. H. Szeto and O. R. Wood II, Applied Physics Letters, Vol. 34, No. 3, Feb. 1, 1979, pp. 213-215.